Orthogonal-path Schedule Algorithm for MSM Clos-network Switching Fabric

Aiming at the issue that the traditional schedule algorithms are usually proposed for the uniform model of MSM (Memory-Space-Memory) Clos-network, it is needed to design a proprietary and dedicated algorithm with corresponding architecture for switching fabric. This paper presents a novel orthogonal path schedule algorithm (OPSA) based on self-designed MSM Clos-network. The algorithm focuses on eliminating the request-grant-accept delay brought by traditional algorithms, such as concurrent dispatching (CD) and concurrent round-robin dispatching (CRRD), and simplifying the system architecture as well as reducing the complexity of hardware design. Specifically, according to the dynamic updated path status between IM and OM, different IMs are dispatched with orthogonal paths that can be used to transmit data without any conflict during each time slot. Besides, variable length packet and fixed-length cells are adopted to accelerate pipe-line processing efficiency. The experimental results show that OPSA we proposed not only can guarantee the switching delay in the proper range, but also can achieve 100% throughput in optimal conditions. In addition, the algorithm complexity of OPSA is obviously decreased, while reducing the hardware consumption.